A gas-liquid two phase flow stream includes a mixture of different fluids having different phases, such as air and water, steam and water, or oil and natural gas. Moreover, the liquid phase of a fluid flow stream may further comprise different liquid components, such as oil and water. A gas-liquid two phase flow takes many different forms and may be classified into various types of gas distribution within the liquid. These classifications are commonly called flow regimes or flow patterns and are illustrated in FIGS. 1A-1E. Bubble flow as illustrated in FIG. 1A is typically a continuous distribution of liquid with a fairly even dispersion of bubbles in the liquid. Slug or plug flow as illustrated in FIG. 1B is a transition from bubble flow where the bubbles have coalesced into larger bubbles with a size approaching the diameter of the tube. Churn flow as illustrated in FIG. 1C is a pattern where the slug flow bubbles have connected to one another. In annular flow as illustrated in FIG. 1D, liquid flows on the wall of the tube as a film and the gas flows along the center of the tube. Finally, in wispy annular flow as illustrated in FIG. 1E, as the liquid flow rate is increased, the concentration of drops in the gas core increases, leading to the formation of large lumps or streaks of liquid.
It is often desirable to separate the gas and liquid components of a fluid from one another to enable proper operation of systems, such as certain types of liquid pumps. Conventional vertical or horizontal gas-liquid separators are available to separate gas from liquid. Conventional separators typically employ mechanical structures, wherein an incoming fluid strikes a diverting baffle which initiates primary separation between the gas and liquid components. Mesh pads or demister pads are then used to further remove suspended liquid. The sizing of a separator and the particular characteristics of the separator is dependent upon many factors, which may include, the flow rate of the liquid, the liquid density, the vapor density, the vapor velocity, and inlet pressure. Vertical separators are typically selected when the vapor/liquid ratio is high or the total flow rate is low. Horizontal separators are typically preferred for low vapor/liquid ratio or for large volumes of total fluid.
One application of these types of separators is in oil and gas drilling operations. Specifically, a mud-gas separator is used when a kick is experienced in a wellbore during drilling operations. A kick is the flow of formation fluids into the wellbore during drilling operations. If a kick is not quickly controlled, it can lead to a blow out. As part of the process for controlling a kick, the blow-out preventors are activated to close the wellbore and wellbore fluids are slowly circulated out of the wellbore while heavier drilling fluids are pumped into the wellbore. A mud gas separator is used to separate natural gas from drilling fluid as the wellbore fluid is circulated out of the wellbore. Often times, however, prior art separators, have limited capability to process flow streams with high volumes and/or high flow rates, such as those characteristic of wellbores.
Of course, separators are also used in the production of oil and gas to separate natural gas from oil that is being produced. Additionally, there are many other applications that require the use of gas-liquid separators. For example, when supplying fuel to ships, known as bunkering, air is often entrained in the fuel, causing an inaccurate measurement of the transferred fuel. Likewise, in oil production or production of other liquids, transferring or conveying a liquid may result in the liquid acquiring entrained gas during that process, a result observed in pipelines with altered terrains. In this regard, entrained gasses can prevent the accurate measurement of a liquid product, whether it is fuel transferred during bunkering or a liquid flowing in a pipeline.